As UN officials prepare to digest Iraq's declaration of its weapons programmes, the Pentagon is continuing to assemble forces for possible military action.

Administration officials are concerned that the analysis and debate over Iraq's declaration and the inspection process could meander on unresolved

The handover of Iraq's declaration may be a significant political milestone in this unfolding crisis, but senior US defence officials have insisted to the BBC that it is not going to have any impact on what they describe as a "methodical and deliberate" military build-up in the region.

Indeed, the administration is making it clear that, whatever Baghdad's declaration contains, it will not be an immediate trigger for war.

All the indications are that the notional timetable that Pentagon planners are working towards still extends many weeks into the future.

Forward headquarters

While another aircraft carrier has just left for the region, US Navy officials say they expect the carriers currently out there to return as scheduled.

Equally, the man who would run any war with Iraq, General Tommy Franks, is about to test a new forward headquarters in Qatar.

Franks: Testing a new forward HQ in Qatar

But he and his senior staff are also expected to return to the United States after the exercise is over, even if the headquarters itself stays for the time being.

That, of course, could all change if there is any kind of incident. But what the Pentagon is really doing at the moment is making sure that its heavy equipment and supplies - the things that would take time to assemble but which can also be stored if necessary - are in place.

That helps keep the pressure on Baghdad, and would speed-up any final preparations.

Call-up

In terms of the kind of build-up that would be needed for a major campaign, one senior defence official told the BBC: "You haven't seen anything yet."

A tell-tale sign that action may be imminent would be a major call-up of reservists. That will not happen until it is absolutely necessary, because of the disruption it causes.

There have been hints of a limited new call-up, possibly in the next few days. But that will be more to relieve personnel who have been mobilised since the 11 September attacks.

Having said all that, there are signs that administration officials are concerned that the analysis and debate over Iraq's declaration and the inspection process could meander on unresolved.

The question then would be how long the military option could be kept open before a decision had to be made - one way or the other.